In my opinion, the # 1 airline myth is….. that airlines cancel flights due to low load factors.
First of all, when was the last time you were on an empty flight? Second, canceling flights “willy-nilly” just because loads are low simply does not work at a modern network airline where airplanes and crews need to be in place.
There are number of factors an airline considers when it must make a cancellation decision. Among those factors are the reacommodation options available to Customers, equipment routing issues, crew routing issues and many more. Load factor is a consideration from the perspective of the reacommodation options available for the displaced passengers. In other words, it’s easier to reacommodate 30 passengers than 300. If there are two flights, one booked to 30, the other to 130, and the flight with 130 passengers experiences a maintenance problem, it would not be unusual for the airplanes operating these flights to be swapped so that the lowest number of passengers is inconvenienced. Not fun if it happens to you, but from a big picture view, I think it makes perfect sense.
I certainly do understand why your average airline passenger would be suspicious. I think the airlines’ other odd business practices (such as the goofy way they price their product) tend to make one naturally suspicious of anything they say.